Unintended pregnancies may be unwanted pregnancies or mistimed pregnancies.[5] Worldwide, 38% of pregnancies (about 80 million pregnancies) were unintended in 1999 .[6][7] Unintended pregnancies are the main reason for induced abortions,[5] resulting in about 42 million induced abortions;[6] not all unintended pregnancies result in abortions or unwanted children. Unintended pregnancy has been linked to numerous maternal and child health problems.[5]

An intended pregnancy is one that is consciously desired at the time of conception.[5] A pregnancy is intended if either partner intended or desired a pregnancy to occur, though the other partner may not want a pregnancy either at all or at that time, or he/she may be ambivalent to a pregnancy.[5]

Feelings towards a pregnancy can change during the course of a pregnancy. For instance, a change of circumstances might lead to the continued pregnancy being unwanted and perhaps a desire to terminate an initially intended pregnancy. On the other hand, an initially unintended pregnancy might later be welcomed.

Couples often desire to control not just the number of children, but also the timing.[8][9]

Contraceptive failure (the method was used correctly, but did not work.)[6] Contraceptive failure accounts for a relatively small fraction of unintended pregnancies when modern highly effective contraceptives are used.[10] A condom breaking during intercourse or using a condom with a hole in it can lead to malfunctioning contraceptives.

Reasons contraceptives might not have been used or been used incorrectly include:

Coercion. Rape, or even forced pregnancy, which sometimes happens in the context of domestic violence. Unintended pregnancies are more likely to be associated with abuse than intended pregnancies.[11] This may also include birth control sabotage, which is the manipulation of someone's use of birth control to undermine efforts to prevent pregnancy.

Lack of knowledge about sex and reproduction, including erroneous beliefs.

Lack of knowledge or experience with the contraceptive or lack of motivation to use it correctly.

Lack of planning or ambivalence about whether to have a child.

Lack of over-the-counter availability of contraceptives.

Inability or unwillingness to attend healthcare appointments to obtain contraceptives.

A mistaken belief that the woman is infertile, e.g. post-menopausal, previous diagnosis of infertility

Live births: Unless the fetus dies in utero, the result of unintended pregnancies is unintended births. According to one study, over one third of living people in the US under 31 years of age (born since 1982) were the result of unintended pregnancies, a rate that has remained largely unchanged to date.[12]

Pregnancy has risks and potential complications. On average, unintended pregnancies result in poorer outcomes for the mother and for the child, if birth occurs. Unintended pregnancy usually precludes pre-conception counseling and pre-conception care, and sometimes delays initiation of prenatal care.[13] The great majority of abortions result from unintended pregnancies.

Results of unintended pregnancy include:

Prenatal care initiated later, and less adequate.[5] Adversely affects health of woman and of child and less preparation for parenthood.[5] Delay from unintended pregnancy is in addition to that from other risk factors for delay.[5] Unwanted pregnancies have more delay than mistimed.[5]

Greater likelihood of low birth weight, particularly for unwanted pregnancies.[5][16] This may be through increased risk of preterm delivery.[5] In the US, eliminating all unwanted pregnancies would reduce rate of low birth weight by 7% for blacks, and 4% for whites, helping to decrease the large disparity in rates for whites vs. blacks.[5]

Greater infant mortality.[5][16] If all sexually active couples in the US had routinely used effective contraception in 1980, there would have been 1 million fewer abortions, 340,000 fewer live births that were unintended at conception, 5,000 fewer infant deaths, and the infant mortality rate would have been 10% lower.[5]

Likely to be less mentally and physically healthy during childhood.[17]

Abortion, the voluntary termination of pregnancy, is one of the primary consequences of unintended pregnancy.[5] A large proportion of induced abortions worldwide are due to unwanted or mistimed pregnancy.[20][21] Unintended pregnancies result in about 42 million induced abortions per year worldwide.[6] In the United States, over 92% of abortions are the result of unintended pregnancy.[19]

Abortion carries few health risks when performed in accordance with modern medical technique.[5][22][23] It is safer for the pregnant woman than childbirth.[5][24][25] However where safe abortions are not available, abortion can contribute significantly to maternal mortality[26] and morbidity.[22]

While decisions about abortion may cause some individuals psychological distress,[27] some find a reduction in distress after abortion.[5][28] There is no evidence of widespread psychological harm from abortion.[5][29][30] Unwanted pregnancy and births resulting from these pregnancies are also psychologically distressing, so considerations of psychological impact of abortion should be in comparison to potential harm from these stressors.[31][32]

Some find abortion morally objectionable.[5] This could be due to religious beliefs, one's own personal beliefs or the context of the situation.

Over the six years between 1995 and 2000 there were an estimated 338 million pregnancies that were unintended and unwanted worldwide (28% of the total 1.2 billion pregnancies during that period).[33] These unwanted pregnancies resulted in nearly 700,000 maternal deaths (approximately one-fifth of maternal deaths during that period). More than one-third of the deaths were from problems associated with pregnancy or childbirth, but the majority (64%) were from complications from unsafe or unsanitary abortion.[33] Most of the deaths occurred in less developed parts of the world, where family planning and reproductive health services were less available.[33]

Prevention includes comprehensive sexual education, availability of family planning services, abstinence and increased access to a range of effective birth control methods. Most unintended pregnancies result from not using contraception, and many result from using contraceptives inconsistently or incorrectly. Though, increased rates of sexual activity are also a factor.[34]

In the United States, women who have an unintended pregnancy are more likely to have subsequent unplanned pregnancies.[14] Providing family planning and contraceptive services as part of prenatal, postpartum and post abortion care can help reduce recurrence of unintended pregnancy.

Providing contraceptives and family planning services at low or no cost to the user helps prevent unintended pregnancies. Many of those at risk of unintended pregnancy have little income, so even though contraceptives are highly cost-effective,[35] up front cost can be a barrier. Subsidized family planning services improve the health of the population and saves money for governments and health insurers by reducing medical,[13] education and other costs to society.

Providing modern contraceptives to the 201 million women at risk of unintended pregnancy in developing countries who do not have access to contraception would cost an estimated US$3.9 billion per year.[36] This expenditure would prevent an estimated 52 million unintended pregnancies annually, preventing 1.5 million maternal and child deaths annually, and reduce induced abortions by 64% (25 million per year).[36] Reduced illness related to pregnancy would preserve 27 million healthy life years, at a cost of $144 per year of healthy life.[36]

The global rate of unintended pregnancy was 55 per 1,000 women aged 15–44 in 2008, of which 26 per 1,000 ended in abortion.[38] The rate of intended pregnancy was 79 per 1,000.[38] The estimated 208 million pregnancies in 2008 resulted in 102 million intended births, 41 million induced abortions, 33 million unintended births, and 31 million miscarriages.[38]

Globally, the proportion of married women practicing contraception increased from 54% in 1990 to 63% in 2003.[38] The global rate of unintended pregnancy declined from 69 per 1,000 women in 1995.[38] The decline was greatest in the more developed world.[38]

Worldwide, 38% of pregnancies were unintended in 1999 (some 80 million unintended pregnancies in 1999).[6][7] In developed world an estimated 49% of pregnancies were unintended, 36% in the developing world.[7]

The United States rate of unintended pregnancies is higher than the world average, and much higher than that in other industrialized nations.[42] Almost half (49%) of U.S. pregnancies are unintended, more than 3 million unintended pregnancies per year.[10][35]

A 2011 study by the Guttmacher Institute based on data from the Centers for Disease Control and Prevention and other sources determined that the average U.S. rate of unintended pregnancies was 51 per 1,000 women ages 15 to 44 in 2006. Most states' rates were between 40 and 65 unintended pregnancies per 1,000 women. The state with the highest rate of unintended pregnancies was Mississippi, 69 per 1,000 women, followed by California, Delaware, the District of Columbia, Hawaii and Nevada (66 to 67 per 1,000). New Hampshire had the lowest rate, 36 per 1,000 women, followed by Maine, North Dakota, Vermont and West Virginia (37 to 39 per 1,000 women).[43][44]

Over 92% of abortions are the result of unintended pregnancy,[19] unintended pregnancies result in about 1.3 million abortions/year.[6] In 2001, 44% of unintended pregnancies resulted in births, and 42% resulted in induced abortion and the rest in miscarriage.[42] It is estimated that more than half of US women have had an unintended pregnancy by age 45.[45] The U.S. states with the highest levels of abortions performed were Delaware, New York and New Jersey, with rates of 40, 38 and 31 per 1,000 women, respectively. High rates were also seen in the states of Maryland, California, Florida, Nevada and Connecticut (25 to 29 per 1,000 women). The state with the lowest abortion rate was Wyoming, which had less than 1 per 1,000 women, followed by Mississippi, Kentucky, South Dakota, Idaho and Missouri (5 to 6 abortions per 1,000 women). [46][47]

US birth rates declined in the 1970s. Factors that are likely to have led to this decline include: The introduction of the birth control pill in 1960, and its subsequent rapid increase in popularity; the completion of legalization of contraceptives in the 1960s and early 1970s; the introduction of federal funding for family planning in the 1960s and Title X in 1970; increased career and educational gains for women and its consequence of increased opportunity costs; and the legalization of abortion, which was completed in 1973. The decline in birth rate was associated with reductions in the number of children put up for adoption and reduction in the rate of neonaticide.

It is unclear to what extent legalization of abortion may have increased the availability of the procedure.[5] It is estimated that before legalization about 1 million abortions were performed annually.[5] Before legalization, abortion was probably one of the most common criminal activities.[5] Before legalization, an estimated 1,000 to 10,000 women died each year from complications of poorly performed abortions.[5] Legalization was followed by a decrease in pregnancy related deaths in young women, as well as decrease in hospital admissions for incomplete or septic abortions, conditions more common than induced abortion.[5]

The infanticide rate during the first hour of life dropped from 1.41 per 100,000 during 1963 to 1972 to 0.44 per 100,000 for 1974 to 1983; the rate during the first month of life also declined, whereas the rate for older infants rose during this time.[48]

The rate of unintended pregnancy declined significantly from 1987 until 1994, due to increased contraceptive use.[49][50] Since then until 2001 the rate has remained relatively unchanged.[50]

Unintended pregnancies and births in the United States[49]
Rate per 1000 women.

The proportion of births that were unintended at time of conception decreased during the 1970s and early 1980s. Between 1982 and 1988 the proportion of births that were unintended began increasing.[5] In 1990 about 44% of births were unintended at time of conception.[5] The fraction of births that were unintended at time of conception was even higher among lower class women (almost 60%), never-married women (73%) and unmarried teens (86%).[5]

Among lower class women, the rate of unintended pregnancy and unintended birth rose from 1994 to 2001, while it declined for the more affluent women (those >200% of federal poverty level).[50] (Unintended pregnancy rose almost 30% and unintended births rose 50% for those below federal poverty level.) Contraceptive use had been increasing for years, but stopped in the 1990s, and began to decline among lower class women.[51] Cuts in federal and state family planning programs may account for the decreased use of contraceptives and increase in unintended pregnancies.[51]

The public cost of unintended pregnancy is estimated to be about 11 billion dollars per year in short term medical costs.[19] This includes costs of births, one year of infant medical care and costs of fetal loss.[19] Preventing unintended pregnancy would save the public over 5 billion dollars per year in short term medical costs.[19] Savings in long term costs and in other areas would be much larger.[19] By another estimate, the direct medical costs of unintended pregnancies, not including infant medical care, was $5 billion in 2002.[52] The Brookings Institution conducted a research and their results show that taxpayers spend more than $12 billion each year on unintended pregnancies. They also find that, if all unintended pregnancies were prevented, the resulting savings on medical spending alone would equal more than three quarters of the federal FY 2010 appropriation for the Head Start and Early Head Start programs and would be roughly equivalent to the amount that the federal government spends each year on the Child Care and Development Fund (CCDF).[53]

Of the 800,000 teen pregnancies per year,[54] over 80% were unintended in 2001.[6] One-third of teen pregnancies result in abortion.[54] In 2002, about 9% of women at risk for unintended pregnancy were teenagers,[40] but about 20% of the unintended pregnancies in the United States are to teenagers.[55] A somewhat larger proportion of unintended births are reported as mistimed, rather than unwanted, for teens compared to women in general (79% mistimed for teens vs. 69% among all women in 1998).[56]

In 2011, a total of 329,797 babies were born to women aged 15–19 years, for a live birth rate of 31.3 per 1,000 women in this age group.1 This is a record low for U.S. teens in this age group, and a drop of 8% from 2010. Birth rates fell 11% for women aged 15–17 years, and 7% for women aged 18–19 years. While reasons for the declines are not clear, teens seem to be less sexually active, and more of those who are sexually active seem to be using birth control than in previous years.[57]

Abstinence from sexual activity is the only 100 percent effective way to avoid unintended pregnancy.[58]

In the US it is estimated that 52% of unintended pregnancies result from couples not using contraception in the month the woman got pregnant, and 43% result from inconsistent or incorrect contraceptive use; only 5% result from contraceptive failure, according to a report from the Guttmacher Institute.[6] Contraceptive use saved an estimated $19 billion in direct medical costs from unintended pregnancies in 2002.[52]

In 2006, publicly funded family planning services (Title X, medicaid, and state funds) helped women avoid 1.94 million unintended pregnancies, thus preventing about 860,000 unintended births and 810,000 abortions.[59] Without publicly funded family planning services, the number of unintended pregnancies and abortions in the United States would be nearly two-thirds higher among women overall and among teens; the number of unintended pregnancies among lower class women would nearly double[59] The services provided at publicly funded clinics saved the federal and state governments an estimated $5.1 billion in 2008 in short term medical costs.[59] Nationally, every $1.00 invested in helping women avoid unintended pregnancy saved $3.74 in Medicaid expenditures that otherwise would have been needed.[59]

Reducing unintended pregnancy in the United States would be particularly desirable since abortion is such a politically divisive issue.[5]

The CDC encourages men and women to formulate a reproductive life plan, to help them in avoiding unintended pregnancies and to improve the health of women and reduce adverse pregnancy outcomes.[60]

Rape is defined as sexual intercourse that is forced on a person without his or her permission. It may involve physical force, the threat of force, or it may be done against someone who is unable to give consent. Sexual intercourse may be vaginal, anal, or oral, and may involve the use of a body part or an object.[61]

A longitudinal study in 1996 of over 4000 women in the United States followed for 3 years found that the rape-related pregnancy rate was 5.0% among victims aged 12–45 years. Applying that rate to rapes committed in the United States would indicate that there are over 32,000 pregnancies in the United States as a result of rape each year.[62]

Early ways of preventing unwanted pregnancy included withdrawal and various alternatives to intercourse; they are difficult to use correctly and, while much better than no method, have high failure rates compared to modern methods.[8][63] Various devices and medications thought to have spermicidal, contraceptive, abortifacient or similar properties were also used.

Abortions have been induced to prevent unwanted births since antiquity,[5] abortion methods are described in some of the earliest medical texts.[63] The degree of safety of early methods relative to the risks of child birth is unclear.[63]

Infanticide (‘customary neonaticide’) or abandonment (sometimes in the form of exposure) are other traditional way of dealing with babies that were not wanted or that a family could not support.[63] Opinions on the morality or desirability of the practices have changed through history.

Where modern contraceptives are not available, abortion has sometimes been used as a major way of preventing birth. For instance in much of Eastern Europe and the former Soviet republics in the 1980s, desired family size was small, but modern contraceptive methods were not readily available, so many couples relied on abortion, which was legal, safe, and readily accessible, to regulate births.[8] In many cases, as contraceptives became more available the rate of unintended pregnancy and abortion dropped rapidly during the 1990s.[8]

In the 19th and 20th century, the desired number of pregnancies has declined as reductions in infant and childhood mortality have increased the probability that children will reach adulthood. Other factors, such as level of education and economic opportunities for women, have also lead to reductions in the desired number of children.[8] As the number of desired number of children decreases, couples spend more of their reproductive lives trying to avoid unintended pregnancies.[8]

^Centers for Disease Control and Prevention. (2006). "Recommendations to improve preconception health and health care — United States: a report of the CDC/ATSDR Preconception Care Work Group and the Select Panel on Preconception Care.". MMWR55 (RR-6).